COMET UPDATE: ISON IN OUTBURST!, NEW COMET NEVSKI IN OUTBURST, LOVEJOY’S JETS
2013-Nov-14
C/2012 S1 (ISON) in Outburst!
ISON has dramatically brightened over the past few days. The latest observations put the comet around magnitude 5.7 to 6.1 which is a 2+ magnitude increase from this weekend. My own observations from this morning in 10×50 and 30×125 binoculars show a nice ‘lollipop’ comet with a very condensed blue-green head and long narrow tail. The tail was over 1 degree in length even in the 10×50s. The comet may continue to brighten as the outburst is still in its early stages. Whether this outburst will be a short-lived event or the beginning of a more active phase is still to be seen. Visual magnitude and CCD observations are urgently requested (especially CCD observers who can resolve near-nucleus features such as jets, fans and shells). ISON is rapidly approaching its November 28 perihelion and as a result it is becoming more and more difficult to observe low in the dawn sky. Still, observers with access to a clear horizon may be able to follow ISON for another week.
New Comet C/2013 V3 (Nevski) in Outburst
Vitali Nevski discovered a new comet on November 6 UT with a CCD-equipped 0.2-m f/1.5 astrograph. Note, Nevski is also one the of co-discoverers of Comet ISON. Visual estimates around the time of discovery placed the comet at magnitude 13-14. Since then the comet has brightened to between magnitude 8.5 and 9.0. Comet Nevski is a long-period comet and reached perihelion on October 27 UT at a distance of 1.39 AU from the Sun. It is currently located near the border of southwestern Leo and southeastern Cancer.
Lovejoy’s Jets
Not to be left out, C/2013 R1 (Lovejoy) has developed into a nice border-line naked eye comet of magnitude ~5.5. CCD observations posted to various Yahoo group lists over the past week showed a short broad sunward fan. I was able to observe Lovejoy with the VATT 1.8-m two nights ago and found the ‘fan’ to consist of 3 strongly curved jets. Lovejoy is currently in Leo Minor and should slowly brighten as it nears its December 22 perihelion at a distance of 0.81 AU from the Sun.
Comets Encke and C/2013 X1 (LINEAR)
Don’t forget that in addition to the three comets above there are two more comets visible in small telescopes in the morning sky. C/2013 X1 (LINEAR) which had its own major outburst last month is slowly fading as the dust released by the outburst disperses. The comet is a large, very diffuse, low surface brightness object of 8th magnitude. 2P/Encke is only a week from its 0.34 AU perihelion. The comet is a very condensed almost star-like object of magnitude 7.5-8.0. Most observers will probably lose Encke in the next day or two as it is getting very low in the eastern sky during dawn.
The ALPO Comet Section request any observations made of these comets.
- Carl Hergenrother (Acting Co-coordinator of ALPO Comet Section)
